Optimization and design of the permanent magnet guideway with the high temperature superconductor

In order to enhance the levitation and guidance performance of the levitated high temperature superconductor (HTS) bulk over the permanent magnet guideway (PMG), it is necessary to optimize the design of the guideway. First of all, a three dimensional (3D) model of the guideway was built up, through which the influence of the air gap across the guideway on the magnetic field was studied. It was found that the magnetic field 10 mm above the guideway is roughly uniform in the length direction though that 1 mm above the guideway is not continuous. Since generally the levitation gap between the vehicle body and the guideway surface is more than 10 mm, it is possible to simplify the HTS-PMG interaction model from 3D to 2D. Subsequently the levitation and guidance forces of the superconductor with different kinds of permanent magnet guideways were calculated in the 2D model. Provided that the product of the width and the height is 2000 mm(2), the numerical results indicated that the HTS-PMG system is optimum when the width ratio between PMG and HTS is between 1.005 and 1.105.